Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 1 | /* Based on netcat 1.10 RELEASE 960320 written by hobbit@avian.org. |
| 2 | * Released into public domain by the author. |
| 3 | * |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 4 | * Copyright (C) 2007 Denys Vlasenko. |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 5 | * |
| 6 | * Licensed under GPLv2, see file LICENSE in this tarball for details. |
| 7 | */ |
| 8 | |
| 9 | /* Author's comments from nc 1.10: |
| 10 | * ===================== |
| 11 | * Netcat is entirely my own creation, although plenty of other code was used as |
| 12 | * examples. It is freely given away to the Internet community in the hope that |
| 13 | * it will be useful, with no restrictions except giving credit where it is due. |
| 14 | * No GPLs, Berkeley copyrights or any of that nonsense. The author assumes NO |
| 15 | * responsibility for how anyone uses it. If netcat makes you rich somehow and |
| 16 | * you're feeling generous, mail me a check. If you are affiliated in any way |
| 17 | * with Microsoft Network, get a life. Always ski in control. Comments, |
| 18 | * questions, and patches to hobbit@avian.org. |
| 19 | * ... |
| 20 | * Netcat and the associated package is a product of Avian Research, and is freely |
| 21 | * available in full source form with no restrictions save an obligation to give |
| 22 | * credit where due. |
| 23 | * ... |
| 24 | * A damn useful little "backend" utility begun 950915 or thereabouts, |
| 25 | * as *Hobbit*'s first real stab at some sockets programming. Something that |
| 26 | * should have and indeed may have existed ten years ago, but never became a |
| 27 | * standard Unix utility. IMHO, "nc" could take its place right next to cat, |
| 28 | * cp, rm, mv, dd, ls, and all those other cryptic and Unix-like things. |
| 29 | * ===================== |
| 30 | * |
| 31 | * Much of author's comments are still retained in the code. |
| 32 | * |
| 33 | * Functionality removed (rationale): |
| 34 | * - miltiple-port ranges, randomized port scanning (use nmap) |
| 35 | * - telnet support (use telnet) |
| 36 | * - source routing |
| 37 | * - multiple DNS checks |
| 38 | * Functionalty which is different from nc 1.10: |
| 39 | * - Prog in '-e prog' can have prog's parameters and options. |
| 40 | * Because of this -e option must be last. |
| 41 | * - nc doesn't redirect stderr to the network socket for the -e prog. |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 42 | * - numeric addresses are printed in (), not [] (IPv6 looks better), |
| 43 | * port numbers are inside (): (1.2.3.4:5678) |
| 44 | * - network read errors are reported on verbose levels > 1 |
| 45 | * (nc 1.10 treats them as EOF) |
| 46 | * - TCP connects from wrong ip/ports (if peer ip:port is specified |
| 47 | * on the command line, but accept() says that it came from different addr) |
| 48 | * are closed, but nc doesn't exit - continues to listen/accept. |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 49 | */ |
| 50 | |
Denis Vlasenko | b6adbf1 | 2007-05-26 19:00:18 +0000 | [diff] [blame] | 51 | /* done in nc.c: #include "libbb.h" */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 52 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 53 | enum { |
| 54 | SLEAZE_PORT = 31337, /* for UDP-scan RTT trick, change if ya want */ |
| 55 | BIGSIZ = 8192, /* big buffers */ |
| 56 | |
| 57 | netfd = 3, |
| 58 | ofd = 4, |
| 59 | }; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 60 | |
| 61 | struct globals { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 62 | /* global cmd flags: */ |
| 63 | unsigned o_verbose; |
| 64 | unsigned o_wait; |
| 65 | #if ENABLE_NC_EXTRA |
| 66 | unsigned o_interval; |
| 67 | #endif |
| 68 | |
| 69 | /*int netfd;*/ |
| 70 | /*int ofd;*/ /* hexdump output fd */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 71 | #if ENABLE_LFS |
| 72 | #define SENT_N_RECV_M "sent %llu, rcvd %llu\n" |
| 73 | unsigned long long wrote_out; /* total stdout bytes */ |
| 74 | unsigned long long wrote_net; /* total net bytes */ |
| 75 | #else |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 76 | #define SENT_N_RECV_M "sent %u, rcvd %u\n" |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 77 | unsigned wrote_out; /* total stdout bytes */ |
| 78 | unsigned wrote_net; /* total net bytes */ |
| 79 | #endif |
| 80 | /* ouraddr is never NULL and goes thru three states as we progress: |
| 81 | 1 - local address before bind (IP/port possibly zero) |
| 82 | 2 - local address after bind (port is nonzero) |
| 83 | 3 - local address after connect??/recv/accept (IP and port are nonzero) */ |
| 84 | struct len_and_sockaddr *ouraddr; |
| 85 | /* themaddr is NULL if no peer hostname[:port] specified on command line */ |
| 86 | struct len_and_sockaddr *themaddr; |
| 87 | /* remend is set after connect/recv/accept to the actual ip:port of peer */ |
| 88 | struct len_and_sockaddr remend; |
| 89 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 90 | jmp_buf jbuf; /* timer crud */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 91 | |
| 92 | /* will malloc up the following globals: */ |
| 93 | fd_set ding1; /* for select loop */ |
| 94 | fd_set ding2; |
| 95 | char bigbuf_in[BIGSIZ]; /* data buffers */ |
| 96 | char bigbuf_net[BIGSIZ]; |
| 97 | }; |
| 98 | |
| 99 | #define G (*ptr_to_globals) |
| 100 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 101 | #define wrote_out (G.wrote_out ) |
| 102 | #define wrote_net (G.wrote_net ) |
| 103 | #define ouraddr (G.ouraddr ) |
| 104 | #define themaddr (G.themaddr ) |
| 105 | #define remend (G.remend ) |
| 106 | #define jbuf (G.jbuf ) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 107 | #define ding1 (G.ding1 ) |
| 108 | #define ding2 (G.ding2 ) |
| 109 | #define bigbuf_in (G.bigbuf_in ) |
| 110 | #define bigbuf_net (G.bigbuf_net) |
| 111 | #define o_verbose (G.o_verbose ) |
| 112 | #define o_wait (G.o_wait ) |
| 113 | #if ENABLE_NC_EXTRA |
| 114 | #define o_interval (G.o_interval) |
| 115 | #else |
| 116 | #define o_interval 0 |
| 117 | #endif |
| 118 | |
| 119 | /* Must match getopt32 call! */ |
| 120 | enum { |
| 121 | OPT_h = (1 << 0), |
| 122 | OPT_n = (1 << 1), |
| 123 | OPT_p = (1 << 2), |
| 124 | OPT_s = (1 << 3), |
| 125 | OPT_u = (1 << 4), |
| 126 | OPT_v = (1 << 5), |
| 127 | OPT_w = (1 << 6), |
| 128 | OPT_l = (1 << 7) * ENABLE_NC_SERVER, |
| 129 | OPT_i = (1 << (7+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, |
| 130 | OPT_o = (1 << (8+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, |
| 131 | OPT_z = (1 << (9+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, |
| 132 | }; |
| 133 | |
| 134 | #define o_nflag (option_mask32 & OPT_n) |
| 135 | #define o_udpmode (option_mask32 & OPT_u) |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 136 | #if ENABLE_NC_SERVER |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 137 | #define o_listen (option_mask32 & OPT_l) |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 138 | #else |
| 139 | #define o_listen 0 |
| 140 | #endif |
| 141 | #if ENABLE_NC_EXTRA |
| 142 | #define o_ofile (option_mask32 & OPT_o) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 143 | #define o_zero (option_mask32 & OPT_z) |
| 144 | #else |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 145 | #define o_ofile 0 |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 146 | #define o_zero 0 |
| 147 | #endif |
| 148 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 149 | /* Debug: squirt whatever message and sleep a bit so we can see it go by. */ |
| 150 | /* Beware: writes to stdOUT... */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 151 | #if 0 |
Denis Vlasenko | 51742f4 | 2007-04-12 00:32:05 +0000 | [diff] [blame] | 152 | #define Debug(...) do { printf(__VA_ARGS__); printf("\n"); fflush(stdout); sleep(1); } while (0) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 153 | #else |
Denis Vlasenko | 51742f4 | 2007-04-12 00:32:05 +0000 | [diff] [blame] | 154 | #define Debug(...) do { } while (0) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 155 | #endif |
| 156 | |
Denis Vlasenko | 51742f4 | 2007-04-12 00:32:05 +0000 | [diff] [blame] | 157 | #define holler_error(...) do { if (o_verbose) bb_error_msg(__VA_ARGS__); } while (0) |
| 158 | #define holler_perror(...) do { if (o_verbose) bb_perror_msg(__VA_ARGS__); } while (0) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 159 | |
| 160 | /* catch: no-brainer interrupt handler */ |
| 161 | static void catch(int sig) |
| 162 | { |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 163 | if (o_verbose > 1) /* normally we don't care */ |
| 164 | fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); |
| 165 | fprintf(stderr, "punt!\n"); |
Denis Vlasenko | 5f42d26 | 2007-04-05 20:57:10 +0000 | [diff] [blame] | 166 | exit(1); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 167 | } |
| 168 | |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 169 | /* unarm */ |
| 170 | static void unarm(void) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 171 | { |
| 172 | signal(SIGALRM, SIG_IGN); |
| 173 | alarm(0); |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | /* timeout and other signal handling cruft */ |
| 177 | static void tmtravel(int sig) |
| 178 | { |
| 179 | unarm(); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 180 | longjmp(jbuf, 1); |
| 181 | } |
| 182 | |
| 183 | /* arm: set the timer. */ |
| 184 | static void arm(unsigned secs) |
| 185 | { |
| 186 | signal(SIGALRM, tmtravel); |
| 187 | alarm(secs); |
| 188 | } |
| 189 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 190 | /* findline: |
| 191 | find the next newline in a buffer; return inclusive size of that "line", |
| 192 | or the entire buffer size, so the caller knows how much to then write(). |
| 193 | Not distinguishing \n vs \r\n for the nonce; it just works as is... */ |
| 194 | static unsigned findline(char *buf, unsigned siz) |
| 195 | { |
| 196 | char * p; |
| 197 | int x; |
| 198 | if (!buf) /* various sanity checks... */ |
| 199 | return 0; |
| 200 | if (siz > BIGSIZ) |
| 201 | return 0; |
| 202 | x = siz; |
| 203 | for (p = buf; x > 0; x--) { |
| 204 | if (*p == '\n') { |
| 205 | x = (int) (p - buf); |
| 206 | x++; /* 'sokay if it points just past the end! */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 207 | Debug("findline returning %d", x); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 208 | return x; |
| 209 | } |
| 210 | p++; |
| 211 | } /* for */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 212 | Debug("findline returning whole thing: %d", siz); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 213 | return siz; |
| 214 | } /* findline */ |
| 215 | |
| 216 | /* doexec: |
| 217 | fiddle all the file descriptors around, and hand off to another prog. Sort |
| 218 | of like a one-off "poor man's inetd". This is the only section of code |
| 219 | that would be security-critical, which is why it's ifdefed out by default. |
| 220 | Use at your own hairy risk; if you leave shells lying around behind open |
| 221 | listening ports you deserve to lose!! */ |
| 222 | static int doexec(char **proggie) ATTRIBUTE_NORETURN; |
| 223 | static int doexec(char **proggie) |
| 224 | { |
| 225 | xmove_fd(netfd, 0); |
| 226 | dup2(0, 1); |
| 227 | /* dup2(0, 2); - do we *really* want this? NO! |
| 228 | * exec'ed prog can do it yourself, if needed */ |
| 229 | execvp(proggie[0], proggie); |
| 230 | bb_perror_msg_and_die("exec"); |
| 231 | } |
| 232 | |
| 233 | /* connect_w_timeout: |
| 234 | return an fd for one of |
| 235 | an open outbound TCP connection, a UDP stub-socket thingie, or |
| 236 | an unconnected TCP or UDP socket to listen on. |
| 237 | Examines various global o_blah flags to figure out what to do. |
| 238 | lad can be NULL, then socket is not bound to any local ip[:port] */ |
| 239 | static int connect_w_timeout(int fd) |
| 240 | { |
| 241 | int rr; |
| 242 | |
| 243 | /* wrap connect inside a timer, and hit it */ |
| 244 | arm(o_wait); |
| 245 | if (setjmp(jbuf) == 0) { |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 246 | rr = connect(fd, &themaddr->u.sa, themaddr->len); |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 247 | unarm(); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 248 | } else { /* setjmp: connect failed... */ |
| 249 | rr = -1; |
| 250 | errno = ETIMEDOUT; /* fake it */ |
| 251 | } |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 252 | return rr; |
| 253 | } |
| 254 | |
| 255 | /* dolisten: |
| 256 | listens for |
| 257 | incoming and returns an open connection *from* someplace. If we were |
| 258 | given host/port args, any connections from elsewhere are rejected. This |
| 259 | in conjunction with local-address binding should limit things nicely... */ |
| 260 | static void dolisten(void) |
| 261 | { |
| 262 | int rr; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 263 | |
| 264 | if (!o_udpmode) |
| 265 | xlisten(netfd, 1); /* TCP: gotta listen() before we can get */ |
| 266 | |
| 267 | /* Various things that follow temporarily trash bigbuf_net, which might contain |
| 268 | a copy of any recvfrom()ed packet, but we'll read() another copy later. */ |
| 269 | |
| 270 | /* I can't believe I have to do all this to get my own goddamn bound address |
| 271 | and port number. It should just get filled in during bind() or something. |
| 272 | All this is only useful if we didn't say -p for listening, since if we |
| 273 | said -p we *know* what port we're listening on. At any rate we won't bother |
| 274 | with it all unless we wanted to see it, although listening quietly on a |
| 275 | random unknown port is probably not very useful without "netstat". */ |
| 276 | if (o_verbose) { |
| 277 | char *addr; |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 278 | rr = getsockname(netfd, &ouraddr->u.sa, &ouraddr->len); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 279 | if (rr < 0) |
| 280 | bb_perror_msg_and_die("getsockname after bind"); |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 281 | addr = xmalloc_sockaddr2dotted(&ouraddr->u.sa); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 282 | fprintf(stderr, "listening on %s ...\n", addr); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 283 | free(addr); |
| 284 | } |
| 285 | |
| 286 | if (o_udpmode) { |
| 287 | /* UDP is a speeeeecial case -- we have to do I/O *and* get the calling |
| 288 | party's particulars all at once, listen() and accept() don't apply. |
| 289 | At least in the BSD universe, however, recvfrom/PEEK is enough to tell |
| 290 | us something came in, and we can set things up so straight read/write |
| 291 | actually does work after all. Yow. YMMV on strange platforms! */ |
| 292 | |
| 293 | /* I'm not completely clear on how this works -- BSD seems to make UDP |
| 294 | just magically work in a connect()ed context, but we'll undoubtedly run |
| 295 | into systems this deal doesn't work on. For now, we apparently have to |
| 296 | issue a connect() on our just-tickled socket so we can write() back. |
| 297 | Again, why the fuck doesn't it just get filled in and taken care of?! |
| 298 | This hack is anything but optimal. Basically, if you want your listener |
| 299 | to also be able to send data back, you need this connect() line, which |
| 300 | also has the side effect that now anything from a different source or even a |
| 301 | different port on the other end won't show up and will cause ICMP errors. |
| 302 | I guess that's what they meant by "connect". |
| 303 | Let's try to remember what the "U" is *really* for, eh? */ |
| 304 | |
| 305 | /* If peer address is specified, connect to it */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 306 | remend.len = LSA_SIZEOF_SA; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 307 | if (themaddr) { |
| 308 | remend = *themaddr; |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 309 | xconnect(netfd, &themaddr->u.sa, themaddr->len); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 310 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 311 | /* peek first packet and remember peer addr */ |
| 312 | arm(o_wait); /* might as well timeout this, too */ |
| 313 | if (setjmp(jbuf) == 0) { /* do timeout for initial connect */ |
| 314 | /* (*ouraddr) is prefilled with "default" address */ |
| 315 | /* and here we block... */ |
| 316 | rr = recv_from_to(netfd, NULL, 0, MSG_PEEK, /*was bigbuf_net, BIGSIZ*/ |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 317 | &remend.u.sa, &ouraddr->u.sa, ouraddr->len); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 318 | if (rr < 0) |
| 319 | bb_perror_msg_and_die("recvfrom"); |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 320 | unarm(); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 321 | } else |
| 322 | bb_error_msg_and_die("timeout"); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 323 | /* Now we learned *to which IP* peer has connected, and we want to anchor |
| 324 | our socket on it, so that our outbound packets will have correct local IP. |
| 325 | Unfortunately, bind() on already bound socket will fail now (EINVAL): |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 326 | xbind(netfd, &ouraddr->u.sa, ouraddr->len); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 327 | Need to read the packet, save data, close this socket and |
| 328 | create new one, and bind() it. TODO */ |
| 329 | if (!themaddr) |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 330 | xconnect(netfd, &remend.u.sa, ouraddr->len); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 331 | } else { |
| 332 | /* TCP */ |
| 333 | arm(o_wait); /* wrap this in a timer, too; 0 = forever */ |
| 334 | if (setjmp(jbuf) == 0) { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 335 | again: |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 336 | remend.len = LSA_SIZEOF_SA; |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 337 | rr = accept(netfd, &remend.u.sa, &remend.len); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 338 | if (rr < 0) |
| 339 | bb_perror_msg_and_die("accept"); |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 340 | if (themaddr && memcmp(&remend.u.sa, &themaddr->u.sa, remend.len) != 0) { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 341 | /* nc 1.10 bails out instead, and its error message |
| 342 | * is not suppressed by o_verbose */ |
| 343 | if (o_verbose) { |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 344 | char *remaddr = xmalloc_sockaddr2dotted(&remend.u.sa); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 345 | bb_error_msg("connect from wrong ip/port %s ignored", remaddr); |
| 346 | free(remaddr); |
| 347 | } |
| 348 | close(rr); |
| 349 | goto again; |
| 350 | } |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 351 | unarm(); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 352 | } else |
| 353 | bb_error_msg_and_die("timeout"); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 354 | xmove_fd(rr, netfd); /* dump the old socket, here's our new one */ |
| 355 | /* find out what address the connection was *to* on our end, in case we're |
| 356 | doing a listen-on-any on a multihomed machine. This allows one to |
| 357 | offer different services via different alias addresses, such as the |
| 358 | "virtual web site" hack. */ |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 359 | rr = getsockname(netfd, &ouraddr->u.sa, &ouraddr->len); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 360 | if (rr < 0) |
| 361 | bb_perror_msg_and_die("getsockname after accept"); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 362 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 363 | |
| 364 | if (o_verbose) { |
| 365 | char *lcladdr, *remaddr, *remhostname; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 366 | |
| 367 | #if ENABLE_NC_EXTRA && defined(IP_OPTIONS) |
| 368 | /* If we can, look for any IP options. Useful for testing the receiving end of |
| 369 | such things, and is a good exercise in dealing with it. We do this before |
| 370 | the connect message, to ensure that the connect msg is uniformly the LAST |
| 371 | thing to emerge after all the intervening crud. Doesn't work for UDP on |
| 372 | any machines I've tested, but feel free to surprise me. */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 373 | char optbuf[40]; |
| 374 | int x = sizeof(optbuf); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 375 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 376 | rr = getsockopt(netfd, IPPROTO_IP, IP_OPTIONS, optbuf, &x); |
| 377 | if (rr < 0) |
| 378 | bb_perror_msg("getsockopt failed"); |
| 379 | else if (x) { /* we've got options, lessee em... */ |
| 380 | bin2hex(bigbuf_net, optbuf, x); |
| 381 | bigbuf_net[2*x] = '\0'; |
| 382 | fprintf(stderr, "IP options: %s\n", bigbuf_net); |
| 383 | } |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 384 | #endif |
| 385 | |
| 386 | /* now check out who it is. We don't care about mismatched DNS names here, |
| 387 | but any ADDR and PORT we specified had better fucking well match the caller. |
| 388 | Converting from addr to inet_ntoa and back again is a bit of a kludge, but |
| 389 | gethostpoop wants a string and there's much gnarlier code out there already, |
| 390 | so I don't feel bad. |
| 391 | The *real* question is why BFD sockets wasn't designed to allow listens for |
| 392 | connections *from* specific hosts/ports, instead of requiring the caller to |
| 393 | accept the connection and then reject undesireable ones by closing. |
| 394 | In other words, we need a TCP MSG_PEEK. */ |
| 395 | /* bbox: removed most of it */ |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 396 | lcladdr = xmalloc_sockaddr2dotted(&ouraddr->u.sa); |
| 397 | remaddr = xmalloc_sockaddr2dotted(&remend.u.sa); |
| 398 | remhostname = o_nflag ? remaddr : xmalloc_sockaddr2host(&remend.u.sa); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 399 | fprintf(stderr, "connect to %s from %s (%s)\n", |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 400 | lcladdr, remhostname, remaddr); |
| 401 | free(lcladdr); |
| 402 | free(remaddr); |
| 403 | if (!o_nflag) |
| 404 | free(remhostname); |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | /* udptest: |
| 409 | fire a couple of packets at a UDP target port, just to see if it's really |
| 410 | there. On BSD kernels, ICMP host/port-unreachable errors get delivered to |
| 411 | our socket as ECONNREFUSED write errors. On SV kernels, we lose; we'll have |
| 412 | to collect and analyze raw ICMP ourselves a la satan's probe_udp_ports |
| 413 | backend. Guess where one could swipe the appropriate code from... |
| 414 | |
| 415 | Use the time delay between writes if given, otherwise use the "tcp ping" |
| 416 | trick for getting the RTT. [I got that idea from pluvius, and warped it.] |
| 417 | Return either the original fd, or clean up and return -1. */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 418 | #if ENABLE_NC_EXTRA |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 419 | static int udptest(void) |
| 420 | { |
| 421 | int rr; |
| 422 | |
| 423 | rr = write(netfd, bigbuf_in, 1); |
| 424 | if (rr != 1) |
| 425 | bb_perror_msg("udptest first write"); |
| 426 | |
| 427 | if (o_wait) |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 428 | sleep(o_wait); // can be interrupted! while (t) nanosleep(&t)? |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 429 | else { |
| 430 | /* use the tcp-ping trick: try connecting to a normally refused port, which |
| 431 | causes us to block for the time that SYN gets there and RST gets back. |
| 432 | Not completely reliable, but it *does* mostly work. */ |
| 433 | /* Set a temporary connect timeout, so packet filtration doesnt cause |
| 434 | us to hang forever, and hit it */ |
| 435 | o_wait = 5; /* enough that we'll notice?? */ |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 436 | rr = xsocket(ouraddr->u.sa.sa_family, SOCK_STREAM, 0); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 437 | set_nport(themaddr, htons(SLEAZE_PORT)); |
| 438 | connect_w_timeout(rr); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 439 | /* don't need to restore themaddr's port, it's not used anymore */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 440 | close(rr); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 441 | o_wait = 0; /* restore */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 442 | } |
| 443 | |
| 444 | rr = write(netfd, bigbuf_in, 1); |
| 445 | return (rr != 1); /* if rr == 1, return 0 (success) */ |
| 446 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 447 | #else |
| 448 | int udptest(void); |
| 449 | #endif |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 450 | |
| 451 | /* oprint: |
| 452 | Hexdump bytes shoveled either way to a running logfile, in the format: |
| 453 | D offset - - - - --- 16 bytes --- - - - - # .... ascii ..... |
| 454 | where "which" sets the direction indicator, D: |
| 455 | 0 -- sent to network, or ">" |
| 456 | 1 -- rcvd and printed to stdout, or "<" |
| 457 | and "buf" and "n" are data-block and length. If the current block generates |
| 458 | a partial line, so be it; we *want* that lockstep indication of who sent |
| 459 | what when. Adapted from dgaudet's original example -- but must be ripping |
| 460 | *fast*, since we don't want to be too disk-bound... */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 461 | #if ENABLE_NC_EXTRA |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 462 | static void oprint(int direction, unsigned char *p, unsigned bc) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 463 | { |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 464 | unsigned obc; /* current "global" offset */ |
| 465 | unsigned x; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 466 | unsigned char *op; /* out hexdump ptr */ |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 467 | unsigned char *ap; /* out asc-dump ptr */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 468 | unsigned char stage[100]; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 469 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 470 | if (bc == 0) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 471 | return; |
| 472 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 473 | obc = wrote_net; /* use the globals! */ |
| 474 | if (direction == '<') |
| 475 | obc = wrote_out; |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 476 | stage[0] = direction; |
| 477 | stage[59] = '#'; /* preload separator */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 478 | stage[60] = ' '; |
| 479 | |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 480 | do { /* for chunk-o-data ... */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 481 | x = 16; |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 482 | if (bc < 16) { |
| 483 | /* memset(&stage[bc*3 + 11], ' ', 16*3 - bc*3); */ |
| 484 | memset(&stage[11], ' ', 16*3); |
| 485 | x = bc; |
| 486 | } |
| 487 | sprintf(&stage[1], " %8.8x ", obc); /* xxx: still slow? */ |
| 488 | bc -= x; /* fix current count */ |
| 489 | obc += x; /* fix current offset */ |
| 490 | op = &stage[11]; /* where hex starts */ |
| 491 | ap = &stage[61]; /* where ascii starts */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 492 | |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 493 | do { /* for line of dump, however long ... */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 494 | *op++ = 0x20 | bb_hexdigits_upcase[*p >> 4]; |
| 495 | *op++ = 0x20 | bb_hexdigits_upcase[*p & 0x0f]; |
| 496 | *op++ = ' '; |
| 497 | if ((*p > 31) && (*p < 127)) |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 498 | *ap = *p; /* printing */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 499 | else |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 500 | *ap = '.'; /* nonprinting, loose def */ |
| 501 | ap++; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 502 | p++; |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 503 | } while (--x); |
| 504 | *ap++ = '\n'; /* finish the line */ |
| 505 | xwrite(ofd, stage, ap - stage); |
| 506 | } while (bc); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 507 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 508 | #else |
Denis Vlasenko | 828e2a9 | 2007-07-13 12:37:31 +0000 | [diff] [blame] | 509 | void oprint(int direction, unsigned char *p, unsigned bc); |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 510 | #endif |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 511 | |
| 512 | /* readwrite: |
| 513 | handle stdin/stdout/network I/O. Bwahaha!! -- the select loop from hell. |
| 514 | In this instance, return what might become our exit status. */ |
| 515 | static int readwrite(void) |
| 516 | { |
| 517 | int rr; |
| 518 | char *zp = zp; /* gcc */ /* stdin buf ptr */ |
| 519 | char *np = np; /* net-in buf ptr */ |
| 520 | unsigned rzleft; |
| 521 | unsigned rnleft; |
| 522 | unsigned netretry; /* net-read retry counter */ |
| 523 | unsigned wretry; /* net-write sanity counter */ |
| 524 | unsigned wfirst; /* one-shot flag to skip first net read */ |
| 525 | |
| 526 | /* if you don't have all this FD_* macro hair in sys/types.h, you'll have to |
| 527 | either find it or do your own bit-bashing: *ding1 |= (1 << fd), etc... */ |
| 528 | FD_SET(netfd, &ding1); /* global: the net is open */ |
| 529 | netretry = 2; |
| 530 | wfirst = 0; |
| 531 | rzleft = rnleft = 0; |
| 532 | if (o_interval) |
| 533 | sleep(o_interval); /* pause *before* sending stuff, too */ |
| 534 | |
| 535 | errno = 0; /* clear from sleep, close, whatever */ |
| 536 | /* and now the big ol' select shoveling loop ... */ |
| 537 | while (FD_ISSET(netfd, &ding1)) { /* i.e. till the *net* closes! */ |
| 538 | wretry = 8200; /* more than we'll ever hafta write */ |
| 539 | if (wfirst) { /* any saved stdin buffer? */ |
| 540 | wfirst = 0; /* clear flag for the duration */ |
| 541 | goto shovel; /* and go handle it first */ |
| 542 | } |
| 543 | ding2 = ding1; /* FD_COPY ain't portable... */ |
| 544 | /* some systems, notably linux, crap into their select timers on return, so |
| 545 | we create a expendable copy and give *that* to select. */ |
| 546 | if (o_wait) { |
| 547 | struct timeval tmp_timer; |
| 548 | tmp_timer.tv_sec = o_wait; |
| 549 | tmp_timer.tv_usec = 0; |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 550 | /* highest possible fd is netfd (3) */ |
| 551 | rr = select(netfd+1, &ding2, NULL, NULL, &tmp_timer); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 552 | } else |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 553 | rr = select(netfd+1, &ding2, NULL, NULL, NULL); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 554 | if (rr < 0 && errno != EINTR) { /* might have gotten ^Zed, etc */ |
| 555 | holler_perror("select"); |
| 556 | close(netfd); |
| 557 | return 1; |
| 558 | } |
| 559 | /* if we have a timeout AND stdin is closed AND we haven't heard anything |
| 560 | from the net during that time, assume it's dead and close it too. */ |
| 561 | if (rr == 0) { |
| 562 | if (!FD_ISSET(0, &ding1)) |
| 563 | netretry--; /* we actually try a coupla times. */ |
| 564 | if (!netretry) { |
| 565 | if (o_verbose > 1) /* normally we don't care */ |
| 566 | fprintf(stderr, "net timeout\n"); |
| 567 | close(netfd); |
| 568 | return 0; /* not an error! */ |
| 569 | } |
| 570 | } /* select timeout */ |
| 571 | /* xxx: should we check the exception fds too? The read fds seem to give |
| 572 | us the right info, and none of the examples I found bothered. */ |
| 573 | |
| 574 | /* Ding!! Something arrived, go check all the incoming hoppers, net first */ |
| 575 | if (FD_ISSET(netfd, &ding2)) { /* net: ding! */ |
| 576 | rr = read(netfd, bigbuf_net, BIGSIZ); |
| 577 | if (rr <= 0) { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 578 | if (rr < 0 && o_verbose > 1) { |
| 579 | /* nc 1.10 doesn't do this */ |
| 580 | bb_perror_msg("net read"); |
| 581 | } |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 582 | FD_CLR(netfd, &ding1); /* net closed, we'll finish up... */ |
| 583 | rzleft = 0; /* can't write anymore: broken pipe */ |
| 584 | } else { |
| 585 | rnleft = rr; |
| 586 | np = bigbuf_net; |
| 587 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 588 | Debug("got %d from the net, errno %d", rr, errno); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 589 | } /* net:ding */ |
| 590 | |
| 591 | /* if we're in "slowly" mode there's probably still stuff in the stdin |
| 592 | buffer, so don't read unless we really need MORE INPUT! MORE INPUT! */ |
| 593 | if (rzleft) |
| 594 | goto shovel; |
| 595 | |
| 596 | /* okay, suck more stdin */ |
| 597 | if (FD_ISSET(0, &ding2)) { /* stdin: ding! */ |
| 598 | rr = read(0, bigbuf_in, BIGSIZ); |
| 599 | /* Considered making reads here smaller for UDP mode, but 8192-byte |
| 600 | mobygrams are kinda fun and exercise the reassembler. */ |
| 601 | if (rr <= 0) { /* at end, or fukt, or ... */ |
| 602 | FD_CLR(0, &ding1); /* disable and close stdin */ |
| 603 | close(0); |
| 604 | } else { |
| 605 | rzleft = rr; |
| 606 | zp = bigbuf_in; |
| 607 | } |
| 608 | } /* stdin:ding */ |
| 609 | shovel: |
| 610 | /* now that we've dingdonged all our thingdings, send off the results. |
| 611 | Geez, why does this look an awful lot like the big loop in "rsh"? ... |
| 612 | not sure if the order of this matters, but write net -> stdout first. */ |
| 613 | |
| 614 | /* sanity check. Works because they're both unsigned... */ |
| 615 | if ((rzleft > 8200) || (rnleft > 8200)) { |
| 616 | holler_error("bogus buffers: %u, %u", rzleft, rnleft); |
| 617 | rzleft = rnleft = 0; |
| 618 | } |
| 619 | /* net write retries sometimes happen on UDP connections */ |
| 620 | if (!wretry) { /* is something hung? */ |
| 621 | holler_error("too many output retries"); |
| 622 | return 1; |
| 623 | } |
| 624 | if (rnleft) { |
| 625 | rr = write(1, np, rnleft); |
| 626 | if (rr > 0) { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 627 | if (o_ofile) |
| 628 | oprint('<', np, rr); /* log the stdout */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 629 | np += rr; /* fix up ptrs and whatnot */ |
| 630 | rnleft -= rr; /* will get sanity-checked above */ |
| 631 | wrote_out += rr; /* global count */ |
| 632 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 633 | Debug("wrote %d to stdout, errno %d", rr, errno); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 634 | } /* rnleft */ |
| 635 | if (rzleft) { |
| 636 | if (o_interval) /* in "slowly" mode ?? */ |
| 637 | rr = findline(zp, rzleft); |
| 638 | else |
| 639 | rr = rzleft; |
| 640 | rr = write(netfd, zp, rr); /* one line, or the whole buffer */ |
| 641 | if (rr > 0) { |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 642 | if (o_ofile) |
| 643 | oprint('>', zp, rr); /* log what got sent */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 644 | zp += rr; |
| 645 | rzleft -= rr; |
| 646 | wrote_net += rr; /* global count */ |
| 647 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 648 | Debug("wrote %d to net, errno %d", rr, errno); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 649 | } /* rzleft */ |
| 650 | if (o_interval) { /* cycle between slow lines, or ... */ |
| 651 | sleep(o_interval); |
| 652 | errno = 0; /* clear from sleep */ |
| 653 | continue; /* ...with hairy select loop... */ |
| 654 | } |
| 655 | if ((rzleft) || (rnleft)) { /* shovel that shit till they ain't */ |
| 656 | wretry--; /* none left, and get another load */ |
| 657 | goto shovel; |
| 658 | } |
| 659 | } /* while ding1:netfd is open */ |
| 660 | |
| 661 | /* XXX: maybe want a more graceful shutdown() here, or screw around with |
| 662 | linger times?? I suspect that I don't need to since I'm always doing |
| 663 | blocking reads and writes and my own manual "last ditch" efforts to read |
| 664 | the net again after a timeout. I haven't seen any screwups yet, but it's |
| 665 | not like my test network is particularly busy... */ |
| 666 | close(netfd); |
| 667 | return 0; |
| 668 | } /* readwrite */ |
| 669 | |
| 670 | /* main: now we pull it all together... */ |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 671 | int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 672 | int nc_main(int argc, char **argv) |
| 673 | { |
| 674 | char *str_p, *str_s, *str_w; |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 675 | USE_NC_EXTRA(char *str_i, *str_o;) |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 676 | char *themdotted = themdotted; /* gcc */ |
| 677 | char **proggie; |
| 678 | int x; |
| 679 | unsigned o_lport = 0; |
| 680 | |
| 681 | /* I was in this barbershop quartet in Skokie IL ... */ |
| 682 | /* round up the usual suspects, i.e. malloc up all the stuff we need */ |
| 683 | PTR_TO_GLOBALS = xzalloc(sizeof(G)); |
| 684 | |
| 685 | /* catch a signal or two for cleanup */ |
| 686 | signal(SIGINT, catch); |
| 687 | signal(SIGQUIT, catch); |
| 688 | signal(SIGTERM, catch); |
| 689 | /* and suppress others... */ |
| 690 | #ifdef SIGURG |
| 691 | signal(SIGURG, SIG_IGN); |
| 692 | #endif |
| 693 | signal(SIGPIPE, SIG_IGN); /* important! */ |
| 694 | |
| 695 | proggie = argv; |
| 696 | while (*++proggie) { |
| 697 | if (strcmp(*proggie, "-e") == 0) { |
| 698 | *proggie = NULL; |
| 699 | argc = proggie - argv; |
| 700 | proggie++; |
| 701 | goto e_found; |
| 702 | } |
| 703 | } |
| 704 | proggie = NULL; |
| 705 | e_found: |
Denis Vlasenko | 4b924f3 | 2007-05-30 00:29:55 +0000 | [diff] [blame] | 706 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 707 | // -g -G -t -r deleted, unimplemented -a deleted too |
| 708 | opt_complementary = "?2:vv"; /* max 2 params, -v is a counter */ |
Denis Vlasenko | fe7cd64 | 2007-08-18 15:32:12 +0000 | [diff] [blame] | 709 | getopt32(argv, "hnp:s:uvw:" USE_NC_SERVER("l") |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 710 | USE_NC_EXTRA("i:o:z"), |
| 711 | &str_p, &str_s, &str_w |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 712 | USE_NC_EXTRA(, &str_i, &str_o, &o_verbose)); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 713 | argv += optind; |
| 714 | #if ENABLE_NC_EXTRA |
| 715 | if (option_mask32 & OPT_i) /* line-interval time */ |
| 716 | o_interval = xatou_range(str_i, 1, 0xffff); |
| 717 | #endif |
| 718 | //if (option_mask32 & OPT_l) /* listen mode */ |
| 719 | //if (option_mask32 & OPT_n) /* numeric-only, no DNS lookups */ |
| 720 | //if (option_mask32 & OPT_o) /* hexdump log */ |
| 721 | if (option_mask32 & OPT_p) { /* local source port */ |
| 722 | o_lport = bb_lookup_port(str_p, o_udpmode ? "udp" : "tcp", 0); |
| 723 | if (!o_lport) |
| 724 | bb_error_msg_and_die("bad local port '%s'", str_p); |
| 725 | } |
| 726 | //if (option_mask32 & OPT_r) /* randomize various things */ |
| 727 | //if (option_mask32 & OPT_u) /* use UDP */ |
| 728 | //if (option_mask32 & OPT_v) /* verbose */ |
| 729 | if (option_mask32 & OPT_w) { /* wait time */ |
| 730 | o_wait = xatoi_u(str_w); |
| 731 | } |
| 732 | //if (option_mask32 & OPT_z) /* little or no data xfer */ |
| 733 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 734 | /* We manage our fd's so that they are never 0,1,2 */ |
| 735 | /*bb_sanitize_stdio(); - not needed */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 736 | |
Denis Vlasenko | 5c51a7c | 2007-06-05 20:08:11 +0000 | [diff] [blame] | 737 | if (argv[0]) { |
| 738 | themaddr = xhost2sockaddr(argv[0], |
| 739 | argv[1] |
| 740 | ? bb_lookup_port(argv[1], o_udpmode ? "udp" : "tcp", 0) |
| 741 | : 0); |
| 742 | } |
| 743 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 744 | /* create & bind network socket */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 745 | x = (o_udpmode ? SOCK_DGRAM : SOCK_STREAM); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 746 | if (option_mask32 & OPT_s) { /* local address */ |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 747 | /* if o_lport is still 0, then we will use random port */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 748 | ouraddr = xhost2sockaddr(str_s, o_lport); |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 749 | x = xsocket(ouraddr->u.sa.sa_family, x, 0); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 750 | } else { |
Denis Vlasenko | 5c51a7c | 2007-06-05 20:08:11 +0000 | [diff] [blame] | 751 | /* We try IPv6, then IPv4, unless addr family is |
| 752 | * implicitly set by way of remote addr/port spec */ |
| 753 | x = xsocket_type(&ouraddr, |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 754 | USE_FEATURE_IPV6((themaddr ? themaddr->u.sa.sa_family : AF_UNSPEC),) |
Denis Vlasenko | 5c51a7c | 2007-06-05 20:08:11 +0000 | [diff] [blame] | 755 | x); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 756 | if (o_lport) |
| 757 | set_nport(ouraddr, htons(o_lport)); |
| 758 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 759 | xmove_fd(x, netfd); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 760 | setsockopt_reuseaddr(netfd); |
| 761 | if (o_udpmode) |
| 762 | socket_want_pktinfo(netfd); |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 763 | xbind(netfd, &ouraddr->u.sa, ouraddr->len); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 764 | #if 0 |
| 765 | setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &o_rcvbuf, sizeof o_rcvbuf); |
| 766 | setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf); |
| 767 | #endif |
| 768 | |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 769 | if (OPT_l && (option_mask32 & (OPT_u|OPT_l)) == (OPT_u|OPT_l)) { |
| 770 | /* apparently UDP can listen ON "port 0", |
| 771 | but that's not useful */ |
| 772 | if (!o_lport) |
| 773 | bb_error_msg_and_die("UDP listen needs nonzero -p port"); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 774 | } |
| 775 | |
| 776 | FD_SET(0, &ding1); /* stdin *is* initially open */ |
| 777 | if (proggie) { |
| 778 | close(0); /* won't need stdin */ |
| 779 | option_mask32 &= ~OPT_o; /* -o with -e is meaningless! */ |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 780 | } |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 781 | #if ENABLE_NC_EXTRA |
| 782 | if (o_ofile) |
| 783 | xmove_fd(xopen(str_o, O_WRONLY|O_CREAT|O_TRUNC), ofd); |
| 784 | #endif |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 785 | |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 786 | if (o_listen) { |
| 787 | dolisten(); |
| 788 | /* dolisten does its own connect reporting */ |
| 789 | if (proggie) /* -e given? */ |
| 790 | doexec(proggie); |
| 791 | x = readwrite(); /* it even works with UDP! */ |
| 792 | } else { |
| 793 | /* Outbound connects. Now we're more picky about args... */ |
| 794 | if (!themaddr) |
| 795 | bb_error_msg_and_die("no destination"); |
| 796 | |
| 797 | remend = *themaddr; |
| 798 | if (o_verbose) |
Denis Vlasenko | 7cff01e | 2008-02-02 16:23:43 +0000 | [diff] [blame] | 799 | themdotted = xmalloc_sockaddr2dotted(&themaddr->u.sa); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 800 | |
| 801 | x = connect_w_timeout(netfd); |
| 802 | if (o_zero && x == 0 && o_udpmode) /* if UDP scanning... */ |
| 803 | x = udptest(); |
| 804 | if (x == 0) { /* Yow, are we OPEN YET?! */ |
| 805 | if (o_verbose) |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 806 | fprintf(stderr, "%s (%s) open\n", argv[0], themdotted); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 807 | if (proggie) /* exec is valid for outbound, too */ |
| 808 | doexec(proggie); |
| 809 | if (!o_zero) |
| 810 | x = readwrite(); |
| 811 | } else { /* connect or udptest wasn't successful */ |
| 812 | x = 1; /* exit status */ |
| 813 | /* if we're scanning at a "one -v" verbosity level, don't print refusals. |
| 814 | Give it another -v if you want to see everything. */ |
| 815 | if (o_verbose > 1 || (o_verbose && errno != ECONNREFUSED)) |
Denis Vlasenko | 19507f0 | 2007-04-06 10:41:05 +0000 | [diff] [blame] | 816 | bb_perror_msg("%s (%s)", argv[0], themdotted); |
Denis Vlasenko | 29fe726 | 2007-04-05 20:26:28 +0000 | [diff] [blame] | 817 | } |
| 818 | } |
| 819 | if (o_verbose > 1) /* normally we don't care */ |
| 820 | fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); |
| 821 | return x; |
| 822 | } |